Effect of solution concentration on the structural, optical and electrical properties of SnO2 thin films prepared by spray pyrolysis

Abstract

The aim of this work is the production of tin oxide thin films with a suitable optoelectronic properties required for application as transparent electrodes. Using a simple and inexpensive homemade spray pyrolysis system of tin chloride (SnCl2) onto glass substrates. The motivation for the use of this technique is its simplicity and effectiveness of preparation. The effect of the molarity (0.05–0.25 mol/l) on structural, optical and electrical film properties was investigated. The results obtained with several characterization techniques such as DRX, AFM, UV–visible transmission and four probe points measurements are well consistent and suggest that the prepared films were uniform and well adherent to the substrates. All the films are polycrystalline in nature with a tetragonal structure having a preferential orientation along the (1 1 0) plane. The obtained SnO2 films, not only have an average transmittance greater than 80% in the visible region, but also have an optical band gap between 3.84 and 4.14 eV depending on the spraying solution concentration. Moreover, the measured electrical conductivity at room temperature was found in the order of 102 (Ω cm)−1.